PS2 had so many games that it appealed to almost all gamers. 360 and PS3 are not in the same situation, and neither is the Wii. I think they are splitting the PS2's user base.
A lot of people want to forget or dismiss the fact that a lot of the PS2 library and user base was "casual". I suppose it's because that word wasn't used to scorn those gamers the way it is used by elitists now.